Using the 3x00 roller rockers on iron heads.

[supercharged024]

I'm gathering the parts to put together the carb'd 3400 for my 81 Olds Omega and I know I need some sort of 1.6 rocker arms to keep the camshafts lift specs with the iron heads. I was figuring I'd have to get a set of comps 1.6 rockers. I thought I'd take a closer look at the fasteners on both heads to see if I could get them to work. As you know the iron heads use a guide plate to keep the pushrods in place with screw in studs while the 3400 uses bolts and the non adjustable mounts have a slot in the head with matching slots on the rocker mounts. Well, I decided to shave off the slots from the mounts since having the guideplates will keep the pushrods in alignment while you tighten them down(with a little assistance to ensure they are not constantly rubbing the pushrods) With that simple mod and also just a very slight amount of filing on the main rocker body where the 2 rocker arms almost touch when installed I can now use the factory 1.6 3400 rocker arms on my iron heads.

[Ortie666]

I think its like 1995/6 3100's came with stamped 1.6's and they work on iron heads.. the cross over year, before they became 1.6 rollers

[IsaacHayes]

94-95 and some 96. They are ball/pivot but 1.6:1 ratio and have guide plates and hardened pushrods.

[bszopi]

I think he already installed them. I'm interested in pics!

[geoffinbc]

The only problem i see is if the rockers do turn a bit on the pedestal then the guides will rub the push rods and not be able to easily keep them in aligned. Also you need to check your getting the correct preload on the lifters.

If I were doing this mod I would somehow pin the pedestal in the desired location and ditch the pushrod guides.

[supercharged024]

I only ground the tab off of one side of the mount and cut a groove in the guide plate, that way they stay in place and won't shift.

[WrathOfSocrus]

Are the iron head studs 10mm on top? If so you could take the pedestal and bolt off the 10mm roller fulcrum rockers. You would just need poly locks to keep them down. Or perhaps flip the stock nut. The inside of the stock rollers looks much like the aluminum Scorpion 1.6:1 full rollers. Keep in mind the Scorpion has a hole for 3/8" studs.

[supercharged024]

I first tried sticking the rocker on the stock stud and that wasn't going to work. The stud wasn't tall enough for the way it's designed. Just use the bolts that they come with, they screw right in. It shouldn't be a problem unless you've shaved the heads a lot.

[Joseph Upson]

Been there and done it. Loose the guide plates and use washers for proper spacing. You may have to do a little dremel work at the forward end of the needle bearing housing between adjacent rockers but that's about it. Torque them down good and drive it hard. I never had a problem with mine once they were put in place. Oh yeah, forgot about the beehive springs, they worked well too, all for several years and thousands of miles as you can tell by the brown color. They were new-grey when installed along with the rockers. They were on my old turbocharged iron head 3100 short block combo.
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I didn't use custom pushrods and I don't recall which ones I used. Longer of the two aluminum head rods, push rods from a roller cam V8 chevy, I don't remember but I had them all in hand at the time.